Can you elaborate more on this? It is something I was afraid of, but I've already got a 9.9 outboard to go on it, and I'm thinking I can hook up the remote throttle lever (what's the term for these?) so that it can be controlled from the wheel.
When your boat has way on, you can steer with the rudder based on the water flow past the rudder. When the boat has stopped, your primary means of turning the boat is by prop wash and right or left rudder...the stern moves opposite that direction. With a propeller located behind the rudder, you cannot generate prop wash...thus you lose this control technique. Many small boats that operate with an outboard are set up so the helmsman can reach over the stern and steer by turning the outboard, which provides excellent, if awkward, control over the boat. With a larger boat like a P30, you can't really reach the outboard.
If you really want to go with this boat, bite the bullet, sell the outboard, and spend the money to put an A4 back in...you will enjoy the boat more as it will not be a half-a$$ed patchup, and you'll get half or more of your cost back when you sell.
Just don't offer the current seller too much, with no engine that boat is worth very little, even assuming it doesn't have other issues which impact it potential value.
Outboard on a P30
Pearson 31 inboard or outboard